[feat] zc.recipe.egg: Improve on the fly patches.

Now specified patches are automatically applied on required eggs as well.

src/zc/buildout/easy_install.py

@@ -763,6 +763,9 @@ class Installer(object):
                 else:
                     logger.debug('Adding required %r', str(req))
                 self._log_requirement(ws, req)
+                if patch_dict and req.project_name in patch_dict:
+                    self._env.scan(
+                        self.build(str(req), {}, patch_dict=patch_dict))
                 for dist in self._get_dist(req, ws):
                     self._maybe_add_setuptools(ws, dist)
             if dist not in req:

zc.recipe.egg_/src/zc/recipe/egg/egg.py

@@ -57,17 +57,21 @@ class Eggs(object):
         options['develop-eggs-directory'] = b_options['develop-eggs-directory']
         options['_d'] = options['develop-eggs-directory']  # backward compat.
 
-    def _get_patch_dict(self, options, distribution_list):
+    def _get_patch_dict(self, options, egg=None):
         patch_dict = {}
         global_patch_binary = options.get('patch-binary', 'patch')
+        if egg:
+            egg = re.sub('[<>=].*', '', egg)
+            egg_list = [egg]
+        else:
+            egg_list = [x[:-8] for x in options.keys() if x.endswith('-patches')]
         def get_option(egg, key, default):
-            if len(distribution_list) == 1:
+            if len(egg_list) == 1:
                 return options.get('%s-%s' % (egg, key),
                                    options.get(key, default))
             else:
                 return options.get('%s-%s' % (egg, key), default)
-        for distribution in distribution_list:
-            egg = re.sub('[<>=].*', '', distribution)
+        for egg in egg_list:
             patches = filter(lambda x:x,
                              map(lambda x:x.strip(),
                                  get_option(egg, 'patches', '').splitlines()))
@@ -162,7 +166,7 @@ class Eggs(object):
                     [develop_eggs_dir, eggs_dir]
                     )
             else:
-                patch_dict = self._get_patch_dict(self.options, distributions)
+                patch_dict = self._get_patch_dict(self.options)
                 ws = zc.buildout.easy_install.install(
                     distributions, eggs_dir,
                     links=links,

zc.recipe.egg_/src/zc/recipe/egg/patches.rst

+
+Patching eggs before installation
+---------------------------------
+
+The SlapOS extensions of ``zc.recipe.egg`` supports applying patches before installing eggs.
+
+The syntax is to use a version with the magic string ``SlapOSPatched`` plus the number of
+patches to apply.
+
+
+Let's use a patch for demoneeded egg:
+
+    >>> write(sample_buildout, 'demoneeded.patch',
+    ... r"""diff -ru before/demoneeded-1.1/eggrecipedemoneeded.py after/demoneeded-1.1/eggrecipedemoneeded.py
+    ... --- before/demoneeded-1.1/eggrecipedemoneeded.py 2020-09-08 09:27:36.000000000 +0200
+    ... +++ after/demoneeded-1.1/eggrecipedemoneeded.py 2020-09-08 09:46:16.482243822 +0200
+    ... @@ -1,3 +1,3 @@
+    ... -y=1
+    ... +y="patched demoneeded"
+    ...  def f():
+    ...    pass
+    ... \ No newline at end of file
+    ... """)
+
+First, we install demoneeded directly:
+
+    >>> write(sample_buildout, 'buildout.cfg',
+    ... """
+    ... [buildout]
+    ... parts = demoneeded
+    ...
+    ... [demoneeded]
+    ... recipe = zc.recipe.egg:eggs
+    ... eggs = demoneeded
+    ... find-links = %(server)s
+    ... index = %(server)s/index
+    ... demoneeded-patches =
+    ...   ./demoneeded.patch#4b8ad56711dd0d898a2b7957e9604079
+    ... demoneeded-patch-options = -p2
+    ...
+    ... [versions]
+    ... demoneeded = 1.1+SlapOSPatched001
+    ... """ % dict(server=link_server))
+
+When running buildout, we have a warning that a different version is installed, but that's not fatal.
+
+    >>> print_(system(buildout), end='')
+    Installing demoneeded.
+    patching file eggrecipedemoneeded.py
+    Installing demoneeded 1.1
+    Caused installation of a distribution:
+    demoneeded 1.1+slapospatched001
+    with a different version.
+
+The installed egg has the slapospatched001 marker
+
+    >>> ls(sample_buildout, 'eggs')
+    d  demoneeded-1.1+slapospatched001-pyN.N.egg
+    -  setuptools-0.7-py2.3.egg
+    d  zc.buildout-1.0-py2.3.egg
+
+The code of the egg has been patched:
+
+    >>> import glob
+    >>> import os.path
+    >>> cat(glob.glob(os.path.join(sample_buildout, 'eggs', 'demoneeded-1.1+slapospatched001*', 'eggrecipedemoneeded.py'))[0])
+    y="patched demoneeded"
+    def f():
+      pass
+
+Reset the state and also remove the installed egg
+
+    >>> remove('.installed.cfg')
+    >>> rmdir(glob.glob(os.path.join(sample_buildout, 'eggs', 'demoneeded-1.1+slapospatched001*'))[0])
+
+
+In the previous example we applied patches to an egg installed directly, but
+the same technique can be used to apply patches on eggs installed as dependencies.
+
+In this example we install demo and apply a patch to demoneeded, which is a dependency to demo. 
+
+    >>> write(sample_buildout, 'buildout.cfg',
+    ... """
+    ... [buildout]
+    ... parts = demo
+    ...
+    ... [demo]
+    ... recipe = zc.recipe.egg
+    ... eggs = demo
+    ... find-links = %(server)s
+    ... index = %(server)s/index
+    ... demoneeded-patches =
+    ...   ./demoneeded.patch#4b8ad56711dd0d898a2b7957e9604079
+    ... demoneeded-patch-options = -p2
+    ...
+    ... [versions]
+    ... demoneeded = 1.1+SlapOSPatched001
+    ... """ % dict(server=link_server))
+
+When running buildout, we also have that warning that a different version is installed.
+
+    >>> print_(system(buildout), end='')
+    Installing demo.
+    Getting distribution for 'demo'.
+    Got demo 0.3.
+    patching file eggrecipedemoneeded.py
+    Installing demoneeded 1.1
+    Caused installation of a distribution:
+    demoneeded 1.1+slapospatched001
+    with a different version.
+    Generated script '/sample-buildout/bin/demo'.
+
+The installed egg has the slapospatched001 marker
+
+    >>> ls(sample_buildout, 'eggs')
+    d  demo-0.3-pyN.N.egg
+    d  demoneeded-1.1+slapospatched001-pyN.N.egg
+    -  setuptools-0.7-py2.3.egg
+    d  zc.buildout-1.0-py2.3.egg
+
+If we run the demo script we see the patch was applied:
+
+    >>> print_(system(join(sample_buildout, 'bin', 'demo')), end='')
+    3 patched demoneeded

zc.recipe.egg_/src/zc/recipe/egg/tests.py

@@ -100,6 +100,26 @@ def test_suite():
                zc.buildout.testing.not_found,
                ])
             ),
+        doctest.DocFileSuite(
+            'patches.rst',
+            setUp=setUp, tearDown=zc.buildout.testing.buildoutTearDown,
+            optionflags=doctest.NORMALIZE_WHITESPACE | doctest.ELLIPSIS,
+            checker=renormalizing.RENormalizing([
+               zc.buildout.testing.normalize_path,
+               zc.buildout.testing.normalize_endings,
+               zc.buildout.testing.normalize_script,
+               zc.buildout.testing.normalize_egg_py,
+               zc.buildout.tests.normalize_bang,
+               zc.buildout.tests.normalize_S,
+               zc.buildout.testing.not_found,
+               zc.buildout.testing.easy_install_deprecated,
+               (re.compile(r'[d-]  zc.buildout(-\S+)?[.]egg(-link)?'),
+                'zc.buildout.egg'),
+               (re.compile(r'[d-]  setuptools-[^-]+-'), 'setuptools-X-'),
+               (re.compile(r'eggs\\\\demo'), 'eggs/demo'),
+               (re.compile(r'[a-zA-Z]:\\\\foo\\\\bar'), '/foo/bar'),
+               ])
+            ),
         ]
     if not WINDOWS:
         suites.append(